Debate rages over wheter are needed on mobile phones. Some argue that too few apps are optimized for a processor that powerful. Others argue that quad-core isn't necessary on such a small device. But one area where the power of quad-core is abundantly clear is in gaming. I ran a few graphics-heavy games on the 4X HD, like ShadowGun, World of Goo, and Osmos HD. The games played smoothly and looked terrific on the 4X HD's display. When it comes to mobile gaming--especially games with 3D graphics--Tegra 3 phones have an advantage.

The PCWorld Test Center measured the 4X HD's battery performance by playing a video at full brightness with the audio set at maximum volume. The video file is a high-definition video that plays at 720p continuously in a loop until the battery gives out, at which point the total battery life is logged by either our automated timer application (on Android tablets) or one of our trusty testers standing by with stopwatch in hand. After two passes, the Optimus 4X had an average battery life of 6 hours, 28 minutes. The Galaxy S III had longer battery life by just over an hour (7 hours, 30 minutes), while the HTC EVO 4G LTE ran about a half hour longer than the 4X HD (7 hours, 4 minutes).

Software

The Optimus 4X HD runs the Android Ice Cream Sandwich operating system with an LG-branded user interface running over it, an interface aptly called Optimus UI 3.0. One of its features is QuickMemo, which lets you take notes with your finger. Sadly, this feature was nowhere to be found on our review unit, but LG says that all Optimus 4X HD phones will ship with the app.

I'll admit that I'm not a fan of these manufacturer-built Android user interfaces. I think Android 4.0 is clean, attractive and polished--and doesn't need anything extra added to it. But as much as tech reviewers and consumers complain, manufacturers are going to continue to slap their overlays over Android in order to differentiate their phones from the competition.